Bundles of microwires will be implanted in gustatory cortex and the amygdala (basolateral and central). Upon recovery, animals will be taught to press a bar for tastant reward while ensembles of amygdalocortical (A-C) single-units are recorded from all sites simultaneously (Exp. 1). Ensemble analysis of these data (e.g., coherence-relationships and pattern-recognition) will permit quantification of A-C interactions during taste coding and differences between the coding of hedonically positive (e.g., sucrose) and negative (e.g., quinine, nicotine) tastants. Animals will then be trained to distinguish between more and less desireable tastants, and will receive taste aversion conditioning (TAC) to the former stimulus (Exp. 2). A-C tastant responses before, during, and after TAC will be analyzed. This will reveal whether and when learning-related plasticity emerges in the A-C circuit, and how tastant-specific A-C interactions change as stimulus associations are learned. Finally, the procedure will be repeated in subjects that have received both electrode and cannula implants. The gustatory cortex, amygdala, or parabrachial pons will be inactivated at particular points of TAC (Exp. 3). It will be possible to test the behavioral significance of the observed A-C interactions and patterns of plasticity, by examining the relationship between learning, inactivation, and appearance of neural patterns.